1. Field of the Invention
This invention relates in general, to a document with a pattern or an object representing colored patterns thereon which is difficult to make reproductions of, and more specifically, to patterns made with some specific kinds of coloring matter, which, when reproducted using processes which utilize photosensitive emulsion, including color photography and color copying process, reproductions in a color entirely different from that of the original. Such documents or objects can be utilized as an object whose reproduction is undesirable such as paper money, various kinds of securities and the like, resultantly preventing forgery of such articles of value.
2. Description of the Prior Art
The recently developed technology for reproduction of colored pattern which utilizes sensitive emulsion, such as color photography and the color reproduction process by means of color copyers, is able to reproduce patterns in a color which can be practically recognized to be identical to that of the original. A potential application of this convenient technology to colored objects whose reproduction is undesirable may cause social problems possibly even criminal acts. Particularly when it is utilized for reproduction of paper money, stock-certificates, bond certificates, atamps, checks, drafts, bills of lading, letters of guarantee, credit cards, various certificates, various coupons, various slips, and/or the objects with such nature, and if the reproductions of such objects should circulate in the market place or through various transactions, it would evidently cause disturbances for economic and financial activities, and it would be serious enough not to allow oversight thereof from the viewpoint of maintaining social justice.
Included in the means available in the prior art and which are applicable for prevention of forgery of such objects of value are:
(1) Employment of particular kinds of paper such as the paper having watermarks therein,
(2) Utilization of particular patterns such as fine, minute and/or complicated background camouflages or ground designs and hidden marks,
(3) Utilization of a particular process for representation of patterns such as mandatory employment of particular and sophisticated graving machines for production of plates,
(4) Employment of a particular, sophisticated and expensive printing process such as Sammel druck machines. Each of these means is inevitably accompanied by costwise disadvantage. In addition, the recent development in the aforementioned technology for reproduction of colored patterns to be made by utilizing photosensitive emulsion which is excellent in performance and simple in handling operation, has added another disadvantage to these conventional means for prevention of reproduction of objects representing colored patterns thereon. When a colored object, hereinafter refered to as a document, is reproduced either directly with such color reproduction technology or indirectly with such technology which is utilized for production of blocks or plates with which printing will be made, some magnitude of discrepancy would be recognized between an original and reproduction from the viewpoint of visibility, dimensional distortion of patterns and/or paper quality. However, it is not seldom that even experts have a difficult time identifying a colored object as a reproduction. Particularly, in view of the fact that the ordinary transactions are carried out by personnel which is nonprofessional in the technical field without using time for making sure of the validity of the paper money, the securities and/or the documents to be transferred by some means including direct comparison with the genuine piece, it would be unrealistic to assume that the aforementioned color reproduction technology will not be applied to the undesirable purposes of forgery.
As a result, it is a social demands to provide a document with colored patterns that can be used as valuable documents, which is difficult to make a reproduction of by means of a process for reproduction of colored patterns to be made by utilizing photosensitive emulsion.